diff --git a/src/sagemaker/session.py b/src/sagemaker/session.py
index 2cc18f6989..2ff561d784 100644
--- a/src/sagemaker/session.py
+++ b/src/sagemaker/session.py
@@ -7509,7 +7509,7 @@ def get_model_package_args(
     if source_uri is not None:
         model_package_args["source_uri"] = source_uri
     if model_life_cycle is not None:
-        model_package_args["model_life_cycle"] = model_life_cycle
+        model_package_args["model_life_cycle"] = model_life_cycle._to_request_dict()
     if model_card is not None:
         original_req = model_card._create_request_args()
         if original_req.get("ModelCardName") is not None:
diff --git a/tests/integ/sagemaker/workflow/test_model_create_and_registration.py b/tests/integ/sagemaker/workflow/test_model_create_and_registration.py
index 8f98cd076d..e84c1920f4 100644
--- a/tests/integ/sagemaker/workflow/test_model_create_and_registration.py
+++ b/tests/integ/sagemaker/workflow/test_model_create_and_registration.py
@@ -48,6 +48,7 @@
 from sagemaker.s3 import S3Uploader
 from sagemaker.sklearn import SKLearnModel, SKLearnProcessor
 from sagemaker.mxnet.model import MXNetModel
+from sagemaker.model_life_cycle import ModelLifeCycle
 from sagemaker.workflow.condition_step import ConditionStep
 from sagemaker.workflow.parameters import ParameterInteger, ParameterString
 from sagemaker.workflow.pipeline import Pipeline
@@ -1005,11 +1006,11 @@ def test_model_registration_with_model_life_cycle_object(
         py_version="py3",
         role=role,
     )
-    create_model_life_cycle = {
-        "Stage": "Development",
-        "StageStatus": "In-Progress",
-        "StageDescription": "Development In Progress",
-    }
+    create_model_life_cycle = ModelLifeCycle(
+        stage="Development",
+        stage_status="In-Progress",
+        stage_description="Development In Progress",
+    )
 
     step_register = RegisterModel(
         name="MyRegisterModelStep",
diff --git a/tests/integ/test_model_package.py b/tests/integ/test_model_package.py
index bc8120bd07..1ac8e33fd8 100644
--- a/tests/integ/test_model_package.py
+++ b/tests/integ/test_model_package.py
@@ -103,7 +103,7 @@ def test_update_model_life_cycle_model_package(sagemaker_session):
         inference_instances=["ml.m5.large"],
         transform_instances=["ml.m5.large"],
         model_package_group_name=model_group_name,
-        model_life_cycle=create_model_life_cycle._to_request_dict(),
+        model_life_cycle=create_model_life_cycle,
     )
 
     desc_model_package = sagemaker_session.sagemaker_client.describe_model_package(
diff --git a/tests/unit/test_estimator.py b/tests/unit/test_estimator.py
index 8294eb0039..11cc83a463 100644
--- a/tests/unit/test_estimator.py
+++ b/tests/unit/test_estimator.py
@@ -4369,7 +4369,6 @@ def test_register_default_image(sagemaker_session):
         stage_status="In-Progress",
         stage_description="Sending for Staging Verification",
     )
-    update_model_life_cycle_req = update_model_life_cycle._to_request_dict()
 
     estimator.register(
         content_types=content_types,
@@ -4384,7 +4383,7 @@ def test_register_default_image(sagemaker_session):
         nearest_model_name=nearest_model_name,
         data_input_configuration=data_input_config,
         model_card=model_card,
-        model_life_cycle=update_model_life_cycle_req,
+        model_life_cycle=update_model_life_cycle,
     )
     sagemaker_session.create_model.assert_not_called()
     exp_model_card = {